Trucks and big SUVs come with noticeably larger brakes than compact cars, and that is no accident. Vehicle weight is one of the main things engineers size the brakes around. Here is how mass drives brake design and what it means when you buy parts or add load.
More mass means more heat
Braking turns the vehicle's momentum into heat - see how hot brakes get. A heavier vehicle carries far more momentum at a given speed, so its brakes must absorb and shed much more heat on every stop. That is why heavy trucks and SUVs get bigger rotors, larger pads, and often multi-piston calipers from the factory - to handle the heat without fading.
It is about heat capacity, not one stop
A single hard stop is limited by tire grip, not brake size - see does tire size affect braking and do bigger brakes stop faster. Where the extra weight really demands bigger brakes is repeated stops and long descents, where a small brake on a heavy vehicle would overheat and fade. Bigger brakes give the thermal headroom heavy vehicles need.
Adding weight to your vehicle
Load your vehicle heavily or tow, and you are effectively making it heavier - which is why towing stresses brakes and can cause fade; see why brakes overheat towing. You cannot just bolt on bigger brakes casually, but you can use heavy-duty pads and good fluid and stay within the rating.
What it means for parts
Always fit brakes sized for your specific vehicle and its options - a heavy trim or tow package may use larger brakes than the base model, so match fitment exactly. For heavy or loaded use, choose quality heat-tolerant pads and fresh hardware.